Device for regulating the speed of generators to secure constant potential.



A; L. PARKER. DEVIOE FOB. REGULATING THE SPEED OF GENERATORS T0 SECURE CONSTANT POTENTIAL.

APPLIOAYIOI FILED NOV. 9.1908.

935,051. Patented Sept. 28, 1909;

Y wimp STATES, PATENT OFFICE.

- 1 ARTHUR L.. PARKER, orgoLnvnnm, OHIO. Y

'DEVIGE ron nneuta'rme THE swim or estimations To. sncuan ooNs'rAn'r' 1 Be it known that I, ARTHURL. PARKER, a

citizen ofthe United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Devices for Reg- 'ulating the Speed of Generators'to Secure Constant Potential, of'which the following is a full, clear, and exact description, reference being had to the accompanying draw- My invention relates to a devicejfor reg- 'ulating. the speed at which an electrical vFi ure-l-is adiagrammatic representation generator; Fig'., 2 isan end' elevation ofa 'brake and solenoid for operating the same.

generator is driven, so that the potential across the brushes of the generator may-be kept constant and prevent any appreciable,

increase involtageat the generator brushes. Generally speaking, the, inventioncomprises the elements andcombinationsthereof,

set forth in the accompanying claims. 7

Reference should be had to the accompanying drawings forming apart of this specification, in which v in panZ-of the equalizing .dev ce and the It frequently happens that a generator is driven by a prime mover, the speed of which will vary, sometimes Within narrow limits,

\ and again between very wide limits.

Where a generator is run by the ordinary engine, it frequently happens that the speed is increased covering'short periods of time -and at such times the voltage across the generator brushes will increase. If a .generator adapted to electrically light a train be operativel'y connectedto the mile upon a railway car,'it is quite evident that due to the great variationsln speed at which a a railway train runs, it would cause the greatest range of variations in potential'of the generator. p

As shown in the drawing, the shaft 1 represents a shaft which is directly con nected with the prime mover. Upon the end of this shaft is a ear 2 this ear meshing with a difiereutim mechanism which is operatively connected with the gear 3. This last named gear meshes witha gear 4 upon the shaft 5, which shaft operates the'gen'era- The differential. mechanism .r i atively connects the gears 2 and 3 comprises to the following parts. Upon the shaft 7 is POTENTIAL.

I ator brush malted is a second bevel gear 9 whlchis secure to Sept.

secured a bevelgear 8 and opposite this I ear the gear 3. Boththe gears 9 and 3 are sup-.

ported upon theshaft 7, but have no driving connection therewith.

Between the gears 8 and 9 are a number of conical spur wheels 10 which mesh with both the first mentioned: gears. The gears 10 are loosely mounted upon pins 11, which pins are secured at their inner ends to a collar 12,

outer ends of the pins 11 are secured in an annular member 13, which is provided with which freely rotates upon .the shaft 7 The This strap is secured at one of its ends to I I a fified'upright. 16, andat its opposite end to-ca lever 17. The'proper tension uponthe brake strap "15 is maintainedb means of a sIpri'ng'IS, secured to the end 0 the lever 17 t e strength of the spring 18 being just'sufli-f cient to hold thestrapto allow nom'ovemeht of the shaft 7. 1

The opposite end of theater-1 u atively connected to'the core member 19 of a solenoid 20. The solenoid is connected in shunt across the brushes of the generator and a suitable resistanceis placed in this shunt circuit, so that when the generator is oper-.

ating at the desired voltage, no'current will flow through the solenoid. T t

It will be apparent that when the generator is driven at a speed by the prime mover so as to give thepropervoltage, across the brushes, at such. times, the solenoidj'will be" inactive and the brake 15 will. prevent the. l j will ream member 13, which will carry with 1 shaft 7 from rotating. Therefore gear, 2

it the spurs 10. These spurs will ,rotate about their own axes due to the fact that the i 7 gear 8 is held stationary, and the rotation of the spurs 10 will cause gear 9 to rotate,

which, injturnyrotatesgear 3, causing the rotation of gear 4 and generator shaft -5.

' The various gears 2,- 13', 3 and lareselected of sucha ratio so that at thelow speed of the prime mover, the generator willb'e driven '10 ata speed toggive the desired voltage;

voltage at the brushes. The release"; of the brake band will allow the drum 14 to slip and so allow the shaft 7 and gear 8 to be rotated to a certain extent. This will destroy the previously described relation between gears 8 and 9 and the speed of gear 9 will be reduced by an amount equal to the speed of rotation of gear 8. Consequently, the speed of gears 3 and 4 and generator shaft 5 will be reduced.

As the generator speed is reduced and the voltage becomes normal, the solenoid ceases to act and the mechanism resumes its former operating relations as before described.

While I have shown and described aparticular form of differential mechanism as well as a particular form of brake, it will be obvious that other forms of these devices may be used without departing from the spirit of the invention.

WVherevcr in the specification and claims, I have used the term, prime mover, this term is intended to include any shaft, engine or motor which causes the generator to run.

Itwill be apparent that the construction herein set forth provides an efficient means for operating a generator at a constant potential, and accomplishes this result what ever may be the range of speed of the prime mover.

Having thus described my invention,what I claim is: 1. The combination with agenerator, of aprime mover, a differential mechanism operatively connecting the prime mover and generator, means for holding said diflt'erential mechanism normally from compensating, and means for causing said differential to compensate to reduce the speed of the generator when the voltage across the generator brushes exceeds apredetermined voltage, 1

2. The combination of a generator, of a prime mover, a differential mechanism operatively connecting the same, a brake normally holding the differential mechanism from compensating, and means automatically and proportionately releasing said brake to allow said differential mechanism to compensate to reduce the speed of the generator when the voltage across the generator brushes exceeds a predetermined voltage.

3. The combination, with a generator, of a. prime mover, differential mechanism operatively connecting the prime mover and generator, a brake for normally holding the differential mechanism from compensating, and a solenoid electrically connected with the generator and operatively secured to the brake to automatically and proportionately allow said differential mechanism to compensate to reduce the speed of the generator when the voltage of. the current generated by the generator exceeds a predetermined voltage.

4-. The combination of a driving shaft, and a generator shaft, a generatoroperated by said shaft, a countershaft, a differential mechanism upon said counter shaft, gears connecting the differential mechanism with the first mentioned shafts, a brake normally holding the counter shaft against rotation whereby said differential mechanism will be held from compensation, and means for releasing said brake and allowing the counter shaft to rotate, whereby the differential mechanism will compensate to reduce the speed of the generator-when the voltage of the current generated by the generator exceeds a predetermined voltage.

5. Thecombina-tion of a driving shaft and a generator shaft, a generator operated by said shaft, a counter shaft, a gear fast upon said'shaft, a gear loose upon said shaft, a spur gear operatively connecting the said gears at thecounter shaft, operative connections'between said spur gear and the driving shaft, operative connections between the loose gear upon the countershaft and generator s aft, means for normally holding the countershaft against rotation, and means for releasing the countershaft holding means to permit rotation of the countershaft, whereby the gear fast on the countershaft may rotate relative to the gear loose on the countershaft thereby reducing the speed of the loose gear and the generator when the voltage of the countershaft and the generator shaft, a brake normally holding the countershaft and the gear fast thereon against rotation, a solenoid electrically connected with the generator and operatively connected with the brake, said solenoid being adapted to operate the brake to release the ,same when the voltage of the current generated by the generator exceeds a predetermined voltage, and means for reset ting the brake.

In testimony whereof, I hereunto affix my signature in the presence of two witnesses.

ARTHUR L. PARKER Witnesses:

CURT B. MUELLER, A.J. HUDSON. 

